温度对黄铜微成形镦粗的影响规律研究

Study on the law of temperature influence on brass upsetting microforming

微成形是微细加工技术群体中的一项技术。由于尺寸效应的影响,微成形比传统的塑性成形更为复杂。研究表明:零件微型化导致了尺寸效应,使传统的塑性加工工艺不能直接应用于微成形,材料不能再看作是均质的,而提高温度进行加工有可能抵消掉非均质材料特性。本文通过H62黄铜(直径从4mm到0.5mm)的加热镦粗实验,其结果与冷成形时进行比较,表明温度影响成形结果,加热使得材料流动趋向于均匀,流动应力降低,因此微成形能通过提高加工温度改进成形结果。

Microforming is one of the key techniques in microfabrication technology. Due to size effect, microforming is more complicated than conventional metal forming. The investigations show that the know--how of conventional forming cannot be simply transferred to the microscale. In microforming, the continuum cannot he regarded as a homogeneous one as it can be done in the case of conventional forming, while warm forming is investigated expecting a homogenizing effect. All the upsetting experimental investigations reported in this paper are done on H62 brass （diameter 0.5 to 4mm）, which show that the temperature influences the forming result tending to homogenize the material flow and reduce the flow stress by increasing temperature.